Question: Stephanie has dinner at a cafe and the cost of her meal is $\$21.00$. She would like to leave a $10\%$ tip. What is her total bill including tip?
Explanation: The tip amount is equal to $10\% \times \$21.00$ To calculate a $10\%$ tip, move the decimal point in $\$21.00$ one place to the left. $10\%$ $\times \$21.00$ $\$2.10$ The cost of the meal plus the amount of the tip will equal the total bill amount. $\$21.00 + \$2.10 = $ $\$23.10$ The total cost of the bill is $\$23.10$.